n4ce version 4.10c Service Release is now available to download from our website!
We were recently asked how we process ppm corrections found in DBX files, using the Leica HeXML format. It has come to light that corrections for ppm on Slope Distance were not being applied, but those for Horizontal Distances were.
We have gone through various archived DBX data and noted that in most cases, the ppm has been set to zero! We have also checked GSI and FRT formatted export files and can confirm that ppm corrections are applied to the slope distances correctly and so n4ce will use them.
In all Leica data formats to date, both prism constant and ppm corrections were being applied prior to export, but not HeXML slope measurements. Where horizontal distances are recorded in HeXML files, the ppm correction is applied!
Putting this into context, if we apply a 5ppm correction, this would result in a discrepancy of 0.5mm per 100m. For detail surveys this is negligible, but may come into effect for control surveys or monitoring, where ppm corrections are being applied. Realistically, corrections for curvature and refraction and scale factor projections, may have a bigger influence.
If you have been importing Leica data via the HeXML option with excessively large ppm corrections, then please check any critical data. A new patch, v4.10c, has been uploaded to our website that corrects this issue and can be downloaded at your earliest convenience.
To update, you will need to:
1) Login to the Client Area on the AiC website.
2) If you already have a version of n4ce 4.10 installed, then all you need to do is download the n4ce 4.10c Update Patch.
3) If you are currently running a version prior to n4ce 4.10, then you will need to UNINSTALL that version of n4ce, and use the v4.10c Full Installer.
As normal, the updates are split into USB Licencing (Dongle users) and Software Licencing versions. Please ensure you select the correct one.